Gyoto
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Astronomical objects defined bya a potential/distance. More...
#include <GyotoStandardAstrobj.h>
Public Member Functions | |
Standard () | |
Default constructor. More... | |
Standard (double radmax) | |
Set rmax in constructor. More... | |
Standard (std::string kind) | |
Set kind in constructor. More... | |
Standard (const Standard &) | |
Copy constructor. More... | |
virtual | ~Standard () |
Destructor: does nothing. | |
virtual void | setSafetyValue (double val) |
Set Standard::safety_value_. | |
virtual double | getSafetyValue () const |
Get Standard::safety_value_. | |
virtual int | Impact (Gyoto::Photon *ph, size_t index, Astrobj::Properties *data=NULL) |
Does a photon at these coordinates impact the object? More... | |
virtual double | operator() (double const coord[4])=0 |
Function defining the object interior. More... | |
virtual void | getVelocity (double const pos[4], double vel[4])=0 |
Fluid velocity field. More... | |
virtual double | giveDelta (double coord[8]) |
Maximum δ inside object. More... | |
virtual int | setParameter (std::string name, std::string content, std::string unit="") |
Set parameter by name. More... | |
virtual void | fillElement (FactoryMessenger *fmp) const |
Fill XML section. More... | |
virtual Generic * | clone () const =0 |
Cloner. More... | |
virtual SmartPointer < Metric::Generic > | getMetric () const |
Get the Metric Generic::gg_. | |
virtual void | setMetric (SmartPointer< Metric::Generic >) |
Set the Metric Generic::gg_. | |
virtual double | getRmax () |
Get maximal distance from center of coordinate system. More... | |
virtual double | getRmax (std::string unit) |
Get rmax_ is specified unit. More... | |
const std::string | getKind () const |
Get the kind of the Astrobj (e.g. "Star") | |
virtual void | setRmax (double val) |
Set maximal distance from center of coordinate system. More... | |
virtual void | setRmax (double val, std::string unit) |
Set maximal distance from center of coordinate system. More... | |
virtual void | unsetRmax () |
Set rmax_set_ to 0. More... | |
void | setFlag_radtransf (int flag) |
Set whether the object is optically thin. More... | |
int | getFlag_radtransf () const |
Query whether object is optically thin. More... | |
virtual Quantity_t | getDefaultQuantities () |
Which quantities to compute if know was requested. More... | |
virtual void | setParameters (FactoryMessenger *fmp) |
Main loop in Subcontractor_t function. More... | |
virtual void | processHitQuantities (Photon *ph, double *coord_ph_hit, double *coord_obj_hit, double dt, Astrobj::Properties *data) const |
Fills Astrobj::Properties. More... | |
virtual double | emission (double nu_em, double dsem, double coord_ph[8], double coord_obj[8]=NULL) const |
Specific intensity Iν More... | |
virtual void | emission (double Inu[], double nu_em[], size_t nbnu, double dsem, double coord_ph[8], double coord_obj[8]=NULL) const |
Specific intensity Iν for several values of νem More... | |
virtual double | integrateEmission (double nu1, double nu2, double dsem, double c_ph[8], double c_obj[8]=NULL) const |
∫ν1ν2 Iν dν (or jν) More... | |
virtual void | integrateEmission (double *I, double const *boundaries, size_t const *chaninds, size_t nbnu, double dsem, double *cph, double *co) const |
∫ν1ν2 Iν dν (or jν) More... | |
virtual double | transmission (double nuem, double dsem, double coord[8]) const |
Transmission: exp( αν * dsem ) More... | |
virtual double | operator() (double const data[])=0 |
The actual function. | |
Protected Types | |
typedef Gyoto::SmartPointer < Gyoto::SmartPointee > | Subcontractor_t (Gyoto::FactoryMessenger *) |
A subcontractor builds an object upon order from the Factory. More... | |
Protected Member Functions | |
void | incRefCount () |
Increment the reference counter. Warning: Don't mess with the counter. | |
int | decRefCount () |
Decrement the reference counter and return current value. Warning: Don't mess with the counter. | |
int | getRefCount () |
Get the current number of references. | |
Protected Attributes | |
double | critical_value_ |
See operator()(double const coord[4]) | |
double | safety_value_ |
See operator()(double const coord[4]) | |
SmartPointer < Gyoto::Metric::Generic > | gg_ |
The Metric in this end of the Universe. | |
double | rmax_ |
Maximum distance to the center of the coordinate system [geometrical units]. More... | |
int | rmax_set_ |
Never recompute rmax: it was externally set. More... | |
const std::string | kind_ |
Kind of object (e.g. "Star"...) More... | |
int | flag_radtransf_ |
1 if radiative transfer inside Astrobj, else 0 | |
Friends | |
class | Gyoto::SmartPointer< Gyoto::Astrobj::Standard > |
Astronomical objects defined bya a potential/distance.
Many geometrically thick objects can be defined by the value of a function of the 4 coordinates, and their emission can often be defined in terms of an emission law and of a transmission law.
This is a base class for this standard case which simplifies a lot writting new Astrobjs.
It is either to implement a sub-class of Astrobj::Standard than a sub-class of Astrobj::Generic. In particular, there is no need to implement the Generic::Impact() function. Instead, one needs to implement a few much simpler functions and most of the complex ray-tracing algorithms and heuristics is implemented in Standard::Impact(). It is recommended to read first the introduction in the Gyoto::Astrobj namespace documentation.
The geometrical shape of a Gyoto::Astrobj::Standard object is yielded by a function of the 4 position vector. This function is implemented as operator()(). The velocity field of the fluid is implemented in the getVelocity() method. The emission(), integrateEmission() and transmission() methods implement the radiative transfer primitives for this object. Finally, you may choose to reimplement processHitQuantities() and Impact(), but this should not be necessary (that is the all point of the Standard class).
Like any other Astrobj::Generic sub-classes, an Astrobj::Standard subclass should register an Astrobj::Subcontractor_t function using the Astrobj::Register() function. See also Writing plug-ins for Gyoto .
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inherited |
A subcontractor builds an object upon order from the Factory.
Various classes need to provide a subcontractor to be able to instanciate themselves upon order from the Factory. A subcontractor is a function (often a static member function) which accepts a pointer to a FactoryMessenger as unique parameter, communicates with the Factory using this messenger to read an XML description of the object to build, and returns this objet. SmartPointee::Subcontractor_t* is just generic enough a typedef to cast to and from other subcontractor types: Astrobj::Subcontractor_t, Metric::Subcontractor_t, Spectrum::Subcontractor_t. A subcontractor needs to be registered using the relevant Register() function: Astrobj::Register(), Metric::Register(), Spectrum::Register().
Gyoto::Astrobj::Standard::Standard | ( | ) |
Default constructor.
kind_ = "Default", rmax_ = 0., rmax_set_ = 0.
Gyoto::Astrobj::Standard::Standard | ( | double | radmax) |
Set rmax in constructor.
kind_ = "Default", rmax_ = radmax, rmax_set_ = 1.
Gyoto::Astrobj::Standard::Standard | ( | std::string | kind) |
Set kind in constructor.
kind_ = kind, rmax_ = 0., rmax_set_ = 0.
Gyoto::Astrobj::Standard::Standard | ( | const Standard & | ) |
Copy constructor.
Make a deep copy of an Astrobj::Standard instance
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pure virtualinherited |
Cloner.
This method must be implemented by the various Astrobj::Generic subclasses in order to support cloning:
Cloning is necessary for multi-threading, recommended for interaction with the Yorick plug-in etc.
Implementing it is very straightforward, as long as the copy constructor Generic(const Generic& ) has been implemented:
Implemented in Gyoto::Astrobj::Star, Gyoto::Astrobj::PatternDisk, Gyoto::Astrobj::Disk3D, Gyoto::Astrobj::DynamicalDisk, Gyoto::Astrobj::ThinDisk, Gyoto::Astrobj::Complex, Gyoto::Astrobj::PolishDoughnut, Gyoto::Astrobj::Disk3D_BB, Gyoto::Astrobj::PatternDiskBB, Gyoto::Astrobj::PageThorneDisk, Gyoto::Astrobj::Torus, Gyoto::Astrobj::ThinDiskPL, and Gyoto::Astrobj::FixedStar.
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virtualinherited |
Specific intensity Iν
Called by the default implementation for processHitQuantities().
emission() computes the intensity Iν emitted by the small volume of length dsem, in the emitter's frame. It should take self-absorption along dsem into account.
Reminder :
The equation used for radiative transfer (without absorption) is:
d(Iν/ν3)/dλ = (jν/ν2) [*]
where λ is the integration parameter along the null geodesic.
NB: Let us consider a particular observer, with ν being the frequency measured by this observer, and ds being the proper distance (as measured by the observer) that the photon travels as it moves from λ to λ+dλ along its geodesic. Then it can be shown that:
dλ = ds/ν
This shows that Eq. [*] is homogeneous.
The default implementation returns 1. if optically thick and dsem if optically thin. It allows for a quick implementation of your object for visualization purposes.
nu_em | Frequency at emission [Hz] |
dsem | length over which to integrate inside the object [geometrical units] |
coord_ph | Photon coordinate |
coord_obj | Emitter coordinate at current photon position |
Reimplemented in Gyoto::Astrobj::PatternDisk, Gyoto::Astrobj::PolishDoughnut, Gyoto::Astrobj::UniformSphere, Gyoto::Astrobj::Torus, Gyoto::Astrobj::DynamicalDisk, Gyoto::Astrobj::Disk3D_BB, Gyoto::Astrobj::PageThorneDisk, Gyoto::Astrobj::PatternDiskBB, and Gyoto::Astrobj::ThinDiskPL.
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virtualinherited |
Specific intensity Iν for several values of νem
Called by the default implementation for processHitQuantities().
emission() computes the intensity Iν emitted by the small volume of length dsem. It should take self-absorption along dsem into account.
Same as emission(double nu_em, double dsem, double coord_ph[8], double coord_obj[8]=NULL) const looping on several values of nu_em.
Inu[nbnu] | Output (must be set to a previously allocated array of doubles) |
nu_em[nbnu] | Frequencies at emission |
nbnu | Size of Inu[] and nu_em[] |
dsem | Length over which to integrate inside the object |
coord_ph | Photon coordinate |
coord_obj | Emitter coordinate at current photon position |
Reimplemented in Gyoto::Astrobj::PolishDoughnut.
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virtual |
Fill XML section.
Astrobj implementations should impement fillElement to save their parameters to XML and call the generic implementation to save generic parts such as Flag_radtrans: Generic::fillElement(fmp).
Reimplemented from Gyoto::Astrobj::Generic.
Reimplemented in Gyoto::Astrobj::PolishDoughnut, Gyoto::Astrobj::Star, Gyoto::Astrobj::Torus, Gyoto::Astrobj::UniformSphere, and Gyoto::Astrobj::FixedStar.
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virtualinherited |
Which quantities to compute if know was requested.
Return a Gyoto::Quantity_t suitable as input to Gyoto::Scenery::setRequestedQuantities() to set de default quantities to compute for this object. The default of these defaults GYOTO_QUANTITY_INTENSITY.
Reimplemented in Gyoto::Astrobj::PageThorneDisk.
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inherited |
Query whether object is optically thin.
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virtualinherited |
Get maximal distance from center of coordinate system.
Get maximal distance from center of coordinate system at which a Photon may hit the object.
Child classes may use the rmax_ member to cache this value.
It can also be set using setRmax(). If setRmax has been used to set rmax_, getRmax() must not recompute it.
Reimplemented in Gyoto::Astrobj::Star, and Gyoto::Astrobj::Torus.
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virtualinherited |
Get rmax_ is specified unit.
Call getRmax() and convert result to unit.
unit | string |
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pure virtual |
Fluid velocity field.
Fill vel with the 4-vector velocity of the fluid at 4-position pos.
[in] | pos | 4-position at which to compute velocity; |
[out] | vel | 4-velocity at pos. |
Implemented in Gyoto::Astrobj::Star, Gyoto::Astrobj::UniformSphere, Gyoto::Astrobj::PolishDoughnut, Gyoto::Astrobj::Torus, and Gyoto::Astrobj::FixedStar.
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virtual |
Maximum δ inside object.
Gives the requested integration step δt (in coordinate time t) between two neighbooring points along a portion of geodesic inside an astrobj
coord | input coordinate at which δt is given |
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virtual |
Does a photon at these coordinates impact the object?
Impact() checks whether a Photon impacts the object between two integration steps of the photon's trajectory (those two steps are photon->getCoord(index, coord1) and photon->getCoord(index+1, coord2)). Impact returns 1 if the photon impacts the object between these two steps, else 0. In many cases of geometrically thick obects, the implementation Astrobj::Standard::Impact() will be fine.
Impact will call Generic::processHitQuantities() (which is virtual and may be re-implemented) to compute observable properties on demand: if the data pointer is non-NULL, the object will look in it for pointers to properties which apply to its kind. If a pointer to a property known to this object is present, then the property is computed and store at the pointed-to adress. For instance, all objects know the "intensity" property. If data->intensity != NULL, the instensity is computed and stored in *data->intensity.
If data is non-NULL and only in this case, processHitQuantities() will also call ph->transmit() to update the transmissions of the Photon (see Photon::transmit(size_t, double)). This must not be done if data is NULL (see Astrobj::Complex::Impact() for an explanation).
ph | Gyoto::Photon aimed at the object; |
index | Index of the last photon step; |
data | Pointer to a structure to hold the observables at impact. |
Implements Gyoto::Astrobj::Generic.
Reimplemented in Gyoto::Astrobj::PolishDoughnut.
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virtualinherited |
∫ν1ν2 Iν dν (or jν)
Compute the integral of emission() from ν1 to ν2. The default implementation is a numerical integrator which works well enough and is reasonably fast if emission() is a smooth function (i.e. no emission or absorption lines). If possible, it is wise to implement an analytical solution. It is used by processHitQuantities to compute the "BinSpectrum" quantity which is the most physical: it is the only quantity that can be actually measured directly by a real-life instrument.
Reimplemented in Gyoto::Astrobj::UniformSphere, and Gyoto::Astrobj::Torus.
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virtualinherited |
∫ν1ν2 Iν dν (or jν)
Like double integrateEmission(double nu1, double nu2, double dsem, double c_ph[8], double c_obj[8]) const for each Spectrometer channel.
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pure virtual |
Function defining the object interior.
A potential, distance, or whatever function such that operator()(double const coord[4]) < Standard::critical_value_ if and only if coord is inside the object. This function is used by the default implmenetation of Impact(). If Impact() is overloaded, it is not necessary to overload operator()(double coord[4]). The default implementation throws an error.
Implemented in Gyoto::Astrobj::UniformSphere, Gyoto::Astrobj::PolishDoughnut, and Gyoto::Astrobj::Torus.
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virtualinherited |
Fills Astrobj::Properties.
processHitQuantities fills the requested data in Impact. To use it, you need to call it in the Impact() method for your object in case of hit. It will fill Redshift, Intensity, Spectrum, BinSpectrum and update the Photon's transmission by calling Photon::transmit(), only if data==NULL.
You can overload it for your Astrobj. The generic implementation calls emission(), integrateEmission() and transmission() below.
Reimplemented in Gyoto::Astrobj::PageThorneDisk.
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inherited |
Set whether the object is optically thin.
Set flag indicating that radiative transfer should be integrated, i.e. the object is to be considered optically thin.
flag,: | 1 if optically thin, 0 if optically thick. |
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virtual |
Set parameter by name.
Assume MyKind is a subclass of Astrobj::Generic which has two members (a string StringMember and a double DoubleMember):
If MyKind is not a direct subclass of Generic but is a subclass of e.g. Standard, UniformSphere of ThinDisk, it should call the corresponding setParameter() implementation instead of Generic::setParameter().
name | XML name of the parameter |
content | string representation of the value |
unit | string representation of the unit |
Reimplemented from Gyoto::Astrobj::Generic.
Reimplemented in Gyoto::Astrobj::PolishDoughnut, Gyoto::Astrobj::Star, Gyoto::Astrobj::Torus, Gyoto::Astrobj::UniformSphere, and Gyoto::Astrobj::FixedStar.
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virtualinherited |
Main loop in Subcontractor_t function.
The Subcontractor_t function for each Astrobj kind should look somewhat like this (templated as Gyoto::Astrobj::Subcontractor<MyKind>):
Each object kind should implement setParameter(string name, string content, string unit) to interpret the individual XML elements. setParameters() can be overloaded in case the specific Astrobj class needs low level access to the FactoryMessenger. See UniformSphere::setParameters().
Reimplemented in Gyoto::Astrobj::PatternDisk, Gyoto::Astrobj::Disk3D, Gyoto::Astrobj::Star, Gyoto::Astrobj::UniformSphere, Gyoto::Astrobj::Torus, and Gyoto::Astrobj::Complex.
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virtualinherited |
Set maximal distance from center of coordinate system.
Set maximal distance from center of coordinate system at which a Photon may hit the object.
Side effect: set rmax_set_ to 1.
val | new rmax_ in geometrical units. |
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virtualinherited |
Set maximal distance from center of coordinate system.
Call Generic::setRmax(double val) after converting val from unit to geometrical units.
val | rmax_ expressed in unit "unit"; |
unit | string... |
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virtualinherited |
Transmission: exp( αν * dsem )
transmission() computes the transmission of this fluid element or 0 if optically thick. The default implementation returns 1. (no attenuation) if optically thin, 0. if optically thick.
nuem | frequency in the fluid's frame |
coord | Photon coordinate |
dsem | geometrical length in geometrical units |
Reimplemented in Gyoto::Astrobj::PatternDisk, Gyoto::Astrobj::PolishDoughnut, Gyoto::Astrobj::Torus, and Gyoto::Astrobj::Disk3D_BB.
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virtualinherited |
Set rmax_set_ to 0.
getRmax() will then be free to recompute rmax_. Astrobjs which cache rmax_ may need to update it when unsetRmax() is called.
Reimplemented in Gyoto::Astrobj::Star.
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protectedinherited |
Kind of object (e.g. "Star"...)
The kind should match the name of the class, e.g. "Star" for a Gyoto::Star.
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protectedinherited |
Maximum distance to the center of the coordinate system [geometrical units].
Maximum distance from the center of the coordinate system at which a photon may hit the object. Child classes may choose to update rmax at all time or to use it to cache the value, for instance when getRmax() is called. External classes (Photons in particular) must use getRmax() to access this information.
rmax_set_==1 means that rmax_ was set using setRmax() or the constructor. In this case, getRmax() must always return this value, not recompute it.
rmax_ is in geometrical units.
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protectedinherited |
Never recompute rmax: it was externally set.
rmax_set_==1 means that rmax_ was set using setRmax() or the constructor. In this case, getRmax() must always return this value, not recompute it.
Use unsetRmax() to reset rmax_set_ to 0.